In Germany is the old tradition to stand up and put the hand on the trouser seam and sing loud...but old tradition are often forgotten in Germany! A shame!
It's a sign for respect and sense of belonging. Law enforcers show a military salute to the flag. "Hand on heart" is a replacement for the civillians who prefers to show a sign. In general civillians stand at attention. That's what I prefer.
We almost never sing national anthem in France, maybe because it is one of the most violents in the world...
So that's why a lot of people in France don't know the lyrics...
Hello Sabri.KC, the French anthem is written in violent times, so is clear that the words are violent! Have you ever listen to the Italian anthem? Full of hate against the Austrians and Germans! Or the anthem of Mexico speaks only of war and the thunder of canons! - I think everyone, who lives today, must unterstand when the anthems are written and unter which circumstances! Greetings to France!